From afar it looks like any Bay Area hill, but a closer look at the Coyote Hills Regional Park hillside shows humming birds, flitting butterflies and several striped Caterpillars nesting on milkweed plants in its Nectar Garden. In honor of these residents, the park is preparing to celebrate its 10th annual Butterfly and Bird Festival on Saturday April 25 and is expecting 600 visitors. "The festival is aimed for our community," said Dino Labiste, naturalist at the Coyote Hills Regional Park. The theme of this year's event is "wildlife rehabilitation."

The festival will teach and encourage the local area residents to develop a nectar garden in their backyard and is dedicated to increasing the numbers and species of butterflies and birds in Bay Area landscapes.

There will be booths from various vendors - educational speakers will talk about birds and natural habitats, their importance and on how to grow plants and preserve them. Photographers will talk about different types of migratory birds through slide shows. And Susan Martinek, gardener at the park will give a garden tour, where milkweed plants attract butterflies.

Kids will especially enjoy the Monarch butterfly release in the Nectar Garden at 3 p.m."About 35 Monarch butterflies will be released,'' said Labiste. There will be music, kid's crafts and visitors can buy milkweed plants or nectar plants on sale by the park authorities as well as private vendors.

"Nectar plants are a food source for butterflies," said Martinek, who has been working at the park for the past four years. She said the idea of the event is to educate the public on how to create a natural garden, in their backyard or on their porch. "Put a small plant -asclepias or milkweed- in a pot," said Martinek.

The Monarch butterfly has one of the longest migratory routes; it flies from southwestern Canada to the California coastline. The Bay Area is considered the native resting place for many migrating birds and species, such as the Monarch. Martinek said many of these are declining habitats, because we are losing our open space and have erratic climate change. "Monarch is the indicator for the rest of the environment," she said, adding "It reflects the health of our environment."

Jan Southworth, a former naturalist at the park and the founder of the Butterfly and Bird Festival said the Coyote Hills were home to 70 to 100 different species commonly viewed in the Bay Area in the 1940's and 1950's. Today, a springtime hike will reveal only 10 or 12 different species. "There's very little diversity left," she said. Hardly three varieties of butterflies are seen in the area now.

Southworth is passionate about butterflies and still works as a consultant on butterflies at various schools in the Bay Area. She said residents should go to the nursery to enjoy viewing the plants and buy native California plants for their own homes since they require less water and less pesticide. She recommends planting flowers such as Monkey flower, Zinnia, Cosmos, Lupine and Mexican sunflower.

The Nectar Garden landscape that covers one-quarter of the park area has been developed by school volunteers and includes various nectar plants for butterflies as well as migratory birds such as Marsh Wren, Barn Swallow and Tree Swallow. The garden is open throughout the year and provides continuing projects for school children. The garden is pesticide free and requires little water. "The garden attracts lots of humming and song birds. Most of these birds come in and prepare their nest in spring," said Labiste.